Here is a game that I should have lost. I can’t identify where it went so wrong. It feels like I tricked my opponent into unfavourable exchanges later in the game, and so I won.
Can someone please point out the moves where the game really shouln’t have continued the way it did?
I also have the impression that it didn’t start out favourable for black. I think it started to go wrong for black in the lower left. Move 7 on C3 is the wrong joseki. You can take a look at the joseki library at eidogo.com. It states “[Black C3] is unfavourable with this pincer [H4], as the pincer is in the way of [Black]'s extension.” In the following moves you kept worrying about your black group at D6 while white built strength on the right and territory on the left.
I think move 100 on R17 was a mistake by white. It gave you the opportunity to build a large sphere of influence on the right side. Even though white was able to live on the right side around Q11, the pressure you put on the white group gave you enough strength to successfully attack the lower side.
So, I wouldn’t say that you tricked white into unfavourable exchanges. Instead, you were able to either capture Q11 or make profit on the lower side. The key to success was the sphere of influence on the right side. As white, I would have played R14 instead of R17.
What Miguldir said. The lower left started bad for black, and only got worse. That said, the initial joseki mistake at C3 is not that big a deal. Less than ideal, yes, but perfectly recoverable if you just stay calm, and keep from getting surrounded. B2 is a bit of a mistake, since it’s gote, and too soon to be scrambling for life. Calmly jump out to the center instead, and there is little to worry about. Still, even with B2, white can’t actually completely seal you in with one move.
D5 to E6 is where things start to really go off the rails, though. All black has to do is play F5 to not get sealed in, and that’s good enough. Instead, you wind up with a weak group just kinda… hanging there. Dead weight. Like an albatross around your neck.
Last mistake in this area: white plays K17, trying to do a preemptive ladder breaker and make something of the D9 cut (white should actually probably pincer at C10 instead). White hands you a free opportunity, and you do not take it. Fix that cut. Or failing that, abandon those stones. By move 57, you’ve given up a lot to save them, and they’re still not actually doing much for you.
You were lucky that your opponent put himself in lots of trouble with the group on the right side. Quite spectacular fail from W. Before that he was clearly ahead, and lost around 50 points because of slight clumsiness.